Over the credits, we see numerous magazines and newspaper articles from the 80's, all of which feature Randy "The Ram" Robinson, a major star. We then flash forward twenty years, where Randy "The Ram" is getting ready for a professional wrestling match in a small, local auditorium. He interacts with the other wrestlers backstage, most of whom are much younger than he is (Randy is acknowledged to be in his 50's). Ironically, though they are foes inside the ring, outside the wrestlers are all friendly and often go drinking together. Randy wins his match, in which he uses a small razor to 'blade' (to cut himself on the forehead to draw blood, making the match more dramatic for the fans). Afterwards Randy is given a meager payday, as the promoter claims the gate was smaller than expected. Randy's manager then poses a 20th anniversary rematch with his most notable opponent, the Ayatollah, which sold out Madison Square garden in the 80's. Randy agrees, hoping this kind of high-profile match could help him get back to the top.

Randy goes home to find he has been locked out of his trailer for not paying his rent. He takes pain medication and falls asleep in the back of his van (a Dodge Ram). The next day he goes to work, loading boxes at a supermarket. At night he goes to a strip club where he has taken a liking to an older stripper named Cassidy (Marisa Tomei). Like Randy, Cassidy is much older than her coworkers but still makes a living. Randy nearly gets in a fight with several young men who are making fun of Cassidy's age.

We see Randy going through his training rituals, which includes bleaching his hair blond, getting tanned and shaving his body. To maintain a chiseled physique at his age, Randy also buys and injects large amounts of steroids and then works out feverishly. His next match is a particularly brutal "hardcore" match, in which Randy and his opponent (real life wrestler Dylan Summers, a.k.a. Necro Butcher) use various weapons on each other, including thumbtacks, staple guns, barbed wire and glass. Randy suffers numerous gashes, includes a deep cut on his chest from the barbed wire. After the match Randy is treated by doctors backstage, but soon collapses.

Randy wakes up in a hospital to learn that he suffered a heart attack, necessitating a bypass operation. His doctor warns Randy that unless he cuts out the drugs and stops wrestling, his life could be in danger. Randy goes home, significantly weakened. He follows the doctor's advice, giving up his pills and even canceling all of his upcoming matches. He takes longer hours at the supermarket to make ends meet. Randy realizes how close to death he was, and how alone in life he is. He goes back to the strip club and tells Cassidy about his heart attack, and she breaks one of her rules by agreeing to meet him outside to talk. He tells her how alone he feels, and she suggests he try to rekindle a relationship with his daughter, Stephanie. As first hesitant, Randy agrees.

Randy goes to Stephanie's home, where she refuses to have anything to do with him, cursing him out for never being there during her childhood before walking away. Randy goes back to the strip club, tells Cassidy what happened, so she offers to help Randy find a present for Stephanie. They go to a vintage shop, buy Stephanie a jacket, then Randy convinces Cassidy to have a beer with him. They talk, and Randy eventually kisses her. At first she fully embraces him, but then suddenly pushes him away, not wanting to break her rule of no contact with customers. Cassidy finishes her beer and leaves.

Randy goes to see Stephanie and gives her two gifts. One, a gag gift (a shiny jacket with the letter 'S' embroidered on it) and then a nice peacoat to keep her warm. Stephanie reluctantly agrees to spend the afternoon with him. They walk by the boardwalk, talk, and Randy confesses that he has not been a good father. But with his career finished, he wants to have the relationship with his daughter he never had. Stephanie warms to him, thinks he might be trying to be a good father, and agrees to meet him for dinner that weekend.

A few days later Randy goes to a convention to sign memorabilia for fans, and sees several old wrestlers, many of whom are disabled or wrecks. Randy goes to a wrestling show as a spectator, where he clearly misses being in the ring. After the show he goes out with the other wrestlers, gets drunk, and ends up doing cocaine and having sex with a fan. He gets home, only to realize that he was supposed to be with Stephanie that night. He goes to her home in the middle of the night to apologize, but Stephanie is in tears, saying that she waited two hours for him to show up. She says he has never been and never will be a father to her. That he cannot change who he is, and that she never wants to see him again before throwing him out of the house. Randy leaves, and goes to the strip club. He tries to talk to Cassidy about their embrace, but she says it was a mistake and blows him off, saying that he is nothing but a customer. Randy insults her and is thrown out of the club. Dejected and alone, Randy goes to work the next day. His blood boiling while dealing with finicky customers, Randy accidentally cuts himself in the deli meat slicer, screams at his boss and quits his job. As he leaves, blood everywhere, he later calls up the promoter and tells him he wants to wrestle the last match with the Ayatollah.

We see Randy dying his hair and tanning himself, then packing up his trailer with all of his belongings. Cassidy arrives just as Randy is leaving and apologizes, saying there is something between them but she was afraid to let him get close. Randy seems to have resigned himself to the fact that he is meant to be alone, and drives off, passing her a flyer for the match. Randy drives to the arena and greets the Ayatollah (actually a used car salesman named Bob). They catch up and prepare for the match. As Randy is getting ready for the match, Cassidy arrives at the arena and finds him about to go out to the ring. She warns him that his heart could give out if he wrestles, but he shrugs it off. Randy says that the real world doesn't care about him, and the only place he belongs is in the ring. Cassidy tells him she wants to be with him, but Randy heads to the ring as his music blares.

Before the match, Randy gives a speech thanking the fans, telling them how he's lived his life burning the candle from both ends. But even though people told him he'd never wrestle again, here he is. The match begins, and the crowd is into it. But as it progresses, Randy starts deviates from the planned match, infuriating Bob/Ayatollah who begins to work him harder. We realize that Randy is doing this on purpose, that he wants his heart to give out. Randy goes so far as to steal one of the Ayatollah's signature moves (a big wrestling no-no), pissing off Bob/Ayatollah more. As the match winds down, Randy feels his heart giving out, and he can barely stand. Bob/Ayatollah realizes this and tries to end the match to save Randy's life, but Randy refuses to stop. Randy looks into the crowd, but cannot see Cassidy. Finally Randy climbs to the top rope to deliver his signature "Ram Jam" finisher, his heart ready to burst. Randy salutes the fans, his face covered in tears and sweat. He then leaps off the top rope, and the screen fades to black.